2.6.33-longterm review patch. If anyone has any objections, please let us know.

------------------

From: Namhyung Kim <namhyung@gmail.com>

commit 01393f3d5836b7d62e925e6f4658a7eb22b83a11 upstream.

Check pers->hot_remove_disk instead of pers->hot_add_disk in slot_store()during disk removal. The linear personality only has ->hot_add_disk andno ->hot_remove_disk, so that removing disk in the array resulted tofollowing kernel bug: